测定放射性同位素气体在肺内的分布,可了解肺部各区域的通气及血流情况。这比分侧肺功能试验进步。分侧肺功能试验仅能分别测定左右肺功能,且须行气管插管,病人有一定痛苦或不适。放射性同位素测定肺功能则较简单,安全,不痛苦。1957年以来已渐在临床上广泛使用,对判断肺功能较差的病人能否作胸腔手术,有很大帮助。最常用的气体为氙~(133), Determination of radioisotope gas distribution in the lungs to understand the various regions of the lung ventilation and blood flow. This score side lung function test progress. Sub-lateral lung function tests can only determine the left and right lung function, and to be tracheal intubation, the patient has some pain or discomfort. Radioisotope determination of lung function is relatively simple, safe, not painful. Since 1957, it has been gradually used clinically extensively, which is of great help in judging whether patients with poor lung function can perform thoracic surgery. The most commonly used gas is xenon ~ (133),